Broaching machine



Nov. 15, 1938. F. s. FLoETER Y 2,136,630

BROACHING MACHINE l w Filed DGO. 17, 1956 v ATTORNEY Patented Nov. 15, 1938 UNITEDA STATES PATENT F FICE v 2,136,6e0r

BRoAcHING iimcinNE Frederick S. Floeter, Saginaw,.Mich., assignor to Wickes Bros., Saginaw,` Mich., a corporation. of Michigan Application December 17, 1936; Serial. No. 116,303

7 Claims. (Cl.` 90-33) This invention is concerned with the problem struct, and capable ofv long continued use withof' turning and facing work pieces by broaching. out harmful Wear.

In machines for doing Work of this character 'Other objects of my present improvement are: the Work piece may be kept immovable during the To provide new, useful and simplified mechacutting operation` if it isto be faced 01T flat, or else nism for supporting the work in fixed position 5,

may be rotated about its longitudinal axis and While moving the broach teeth laterally toward thus bemade cylindric. Each tooth of the broach the Work piece, coincidently With the lengthwise cuts into the work piece -in its regularorder, `removements or cutting strokes of the broach; to movinga chip or shaving of predetermined thickprovide means for regulating and controlling the l0 ness; The aggregate depth of cut is determined rate of such lateralmovement; to provide such a 10` by the number of teeth that engage the work durtooth-feed' regulating device with means Whereing,` onel Working traverse of the broach; usually by the teeth may be fed intothe Work at a steady a suilicient number to bring the Work to the derate or at varying rates duringvthe outward lonsired` size and finish. gitudinal stroke of 4the broach or during the re- 1li` Broaches for this class of Work generally have verse stroke, or during both strokes, or after com- I5 their cutting teeth disposed in one of two ways: pletion of` a Working stroke, Whichever the opereither stepped or non-stepped. ator may find best suited to the Work in hand;

In the stepped tooth arrangement the succesto provide a lateral'broach feed device of such sive teeth were offset relatively to each other so character which shall be capable of controlling a that each toothremoved ashaving of equal thicksingle broach that operates upon one face of a 20 ness. The stepped-tooth type of broach had dis- Work piece, `or of controlling two broaches that advantages, one being its lack of adjustability operate simultaneously on opposite sides of the when itmwas desiredtoremove more or less metal Work. per pass. Another was itsinability to compen- The last mentioned dual broach type installasate for tooth wear, tion, which hasbeen chosen for purposes of de- 25 In the l10n-stepped arrangement `the broach SCIlptOl'l herein, has another desirable fatlll'e. teeth all moved in4 a single plane instead of in It Will turn and accurately nsh IOlmd WOrk the great number of mutually Offset, parallel pieces that are'slender` and of small diameter, as planes characteristic of the stepped tooth type. fPr example thevalve Stems 0f internal Combus- U. s; Patent No. 2,039,480 was issued to me May 5, Onffmgnes- Dual'broaches Support Such a Spn- 30 1936, for a broaching machine wherein the broach dlehke Work pece eqlauy 0n Opposite Sides and Der was provided with non stepped teeth. The thus prevent axial springing 0f the Work. Since v lateral o1, feeding n movement of the teeth was tWo cutsare'taken simultaneously the production accomplished by moving the Work piece bodily fate 1S practlcany doubledsidewise toward the broach, during the longitudi- With the OI'egOing and certain other objects in 35 nal travel of the broach. `That patented machine Igeggicu appar lerdinphe peclgaons can be readily adjusted to suitldiierent materials` yl Ompns-es e evlces esem ed and l claimed andthe equivalents thereof. and different sizes of work pieces, and its accu- Inthe accompanying drawn racy can be maintained in spite of tooth Wear ,Fi ,1 is a diagrammatic lange. th t `a d re eated reshar enin s I-I ev r i `some g' I? 1eWO e rav- 40 ,n ,p p g .0W e n eling work table of a breaching machine embodysituations 1t is not feasible to shift the work piece ing my, invention as it appears when. dual er @Q sidevvisedurmg the stroke of the broach. operating Opposed breaches are emp]0yed My present invention relates more particularly Fie 2 is e diagrammatic plan View of the 1et jOanOVel Combmatlon '01", deYCeS for recpfoat* eral feed-in device forv the broaches shown in 45 ing. the broach and for `coincidently feeding the Fig' `1 omitting the travelling platen on which the broach toward the Work. The improvement is apfeed, device `is uarriei plicable t0 bIOaCheS 0f elthll the stepped type 01 Fig. 3 is a sectionallview, taken on line 3-3 of then0nstepped,a1th0ugh 1t iS primarily adapted Fig. 2, enlarged and partly broken away, showing to the latter. Y n the arrangement ofthe opposed broaches and of 50 A general'ObJeC Ofthe present Improvement' 1S` the guideways inwhich they are mounted on the toprovide a breaching machine of such charplaten. acter, employlng a m1nmum`number 0f WOIkillgl Fig. 4 is a front view ofthe machine, showing partsland movingfiointsl, allof which are simple diagrammatically thelocationV of the rack and in design, durable, relatively inexpensive tocongearmechanism-on thetraveling-` platen adapted 55 to impart lateral movementl to the broach teeth during the endwise reciprocation of the platen and broaches.

Numeral I, Figs. 1 and 4, designates a rotatable work piece to be machinedv while turning, a1-

though it might be a non-rotatable piece to be l merely faced off. The work piece is here shown as a pin or spindle supported at one end by a lathe center 2 and rotated by means of a centering chuck 3. The center. 2 is retractible endwise to facilitate inserting and removing the work piece and is actuated by a plunger 4 of a hydraulic cylinder 5. Chuck 3 and work piece I are rotated by means of a motor-driven gearing inI housing 1 through a suitable gear reduction unit.

Machining is done by a co-operating pair of opposed broaches 8, 8a, that have lengthwise reciprocatory movement past the work piece, in the direction of the arrows, Figs. l and 2. The broach teeth are arranged with their cutting edges alinedto define a plane substantially tangent to the rotating periphery of the work piece and parallel with a median plane C, which includes the axis of Vrotation of work piece I.

Here it may be explained that although two opposed broaches 8, 8a are illustrated, only one of them, 8, will be referred to at rst in order to describe conveniently the general mode of opera.- tion and scope of my claimedinvention. Certain additional advantages are inherent in the twobroach arrangement 8, 8a, and willbe pointed out later. l

In the embodiment shown in the drawing, Ythe broaches are mounted on and travel with a platen 9 that slides lengthwise along ways I0, Fig. 3, on the machine bed II Theplaten 9 is actuated by the piston rod I2 and piston I3 of,` an hydraulic cylinder I4, which is mounted in fixed position cn the machine bed, as shown in Figs. 1 and 4.

A mechanism for feeding the teeth into the work is mounted to travel withoron the platen 9, and moves theV broach laterally kand coincidentally with its reciprocation, in a manner now to be described. 1

Platen 9 is provided'with a channel I5, Fig. 3, in which a feed bar I6 is capable of limited lengthwise sliding movement. Y

The slidable bar I6 has its inner face sloped slightly in the direction of its length, presenting a tapered and dovetailed seat. I1, Figs. 2 and 3. A correspondingly tapered and dovetailed guide I member I8, on the back or outer wall of broach 8, engages the seatI'I, enabling broaches 8 to be removed from bars I6.

The tapered seat I'I of feed bar I6, when adjusted lengthwise alongv the channel I5 of the platen 9, gives the.- broach 8 a limited amount of transverse or inward movement relatively to the platen. Abutments or keepers Ill on the platen 9, Fig. l, at the ends of the broach, permit this sidewise movement of the broach 8 while preventing its endwise movement on platen 8.

Broadly, the functioning of the broach 8 and broach-feed bar I6 in the manner above described may be considered as that of a cam. 'Although flat wedge or tapered parts I6, I8 are shown it is obvious that such form is merely one of a number of cam-like arrangements that may be employed without going beyond the scope of my invention as set forth in certain of the claims.

Power means is carried directly upon the platen 9, or else is otherwise arranged to travel with it, for sliding the bar I6 lengthwise and moving the broach 8 crosswise. Such power means is arranged to operate regardlessofnwhether the platen 9 be at an end of its stroke or in the midst of a stroke.

A toothed rack 2I is xed to bar I 6, Fig. 2, and projects beyond its end. A pinion 22 meshes with rack 2l, being fixed to a shaft 23 which is rotatable in bearings 24 on platen 9. Shaft 23 is driven by means of a pinion 25. A rack 26, slidable lengthwise on the traveling platen 9, as shown in Fig. 4, meshes with the pinion 25.

An hydraulic cylinder 2l is mounted upon and carried by platen 9 and has a piston 28 and a piston rod 29 which latter is xed to the sliding rack 26. Cylinder 21 furnishes the power for moving the rack 26 back and forth along the platen.

When oil or other iluid under pressure is applied to cylinder 21 by any suitable means such as a power driven pump (not shown) the lengthwise movement of rack 26 produces rotation of shaft 23, and pinion 22 and the rack 2l shift the broach-feed bar I6 lengthwise a distance determined by the travel of the piston 28. The broach 8 movesV sidewise accordingly.

By regulating the speed of travel of piston 28, the broach 8 can be fed sidewise toward the work piece I at any desired rate. Known fluid control valves may be employed for that purpose.

When the broach has the t or non-stepped type of tooth arrangement as herein shown, an appropriate feed-in motion coincidental with its lengthwise movement is necessary. But if a stepped-tooth broach is employed it is unnecessary to use any power feed device for moving the broach transversely during its cutting stroke, because the stepped arrangement gives the necessary tooth offset for the respective cuts.

The power feed-in means shown can be employed advantageously with the non-stepped type for shifting the position of the broach teeth laterally with respect to the work piece when the broach is at the end of a cutting stroke.

Although I have shown and described a hydraulic cylinder as being a preferred power means for driving the platen back and forth, and have described a hydraulic cylinder carried upon the platen as the preferred power means for reciprocating the slidable bar I6 lengthwise, it is to be understood that the term power means employed in certain of the appended claims is to be interpreted to include power means other than hydraulic; for example, suitable geared electric motors with control switches may be employed for either or both of the services without departing from the claimed invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1.V In a broaching machine including means for supporting a work piece and having a platen mounted for lengthwise reciprocatory movement -past the work piece, power means for reciprocating said platen, a toothed broach mounted on said platen and having the cutting edges of its teeth alined in a plane substantially parallel to the plane of said reciprocatory movement of the platen, power actuatedy mechanism operatively connected to the broach and mounted to travel with said platen, being arranged and adapted to move the broach coincidently with the reciprocatory movement of the platen transversely to a plane defined by the cutting edges of the teeth, toward and away from the work piece.

2. In a broaching machine, in combination, means for supporting and axially rotating a work piece, a broach having teeth with their cutting edges alined ina plane substantially tangent to the periphery of such rotating work piece; power means to impart reciprocating travel to the breach parallel to said plane of the teeth, and means, mounted to travel with the breach during its reciprocations and operative during said reciprecation to impart thereto translatery feedingin movements transverse to said plane, toward the center line of the werk piece.

3. In a breaching machine including means for supporting a work piece and having a platen mounted for lengthwise reciprocatery movement past the werk piece, said platen carrying a toothed broach; power means for reciprocating the platen and broach; a meter mounted on said platen, and means operatively connecting the motor to the broach and arranged and adapted to move the broach, coincidently with the reciprocatery movement ef the platen, in direction transverse to the plane dened by the cutting edges ef the teeth, toward and away from the'werk piece.

4. In a breaching machine including means for supporting a werk piece and a platen mounted for lengthwise reciprocatery movement past the Work piece, a pair of parallel toothed broaches on said platen, spaced apart en opposite sides of the center line thereof, power means for reciprocating the platen and breaches; a motor mounted on said platen and travelling therewith; and means operatively connecting the meter to the respective broaches and arranged and adapted te move the same coincidently with the movements of the platen, in directions transverse to a plane defined by the cutting edges of the broach teeth, whereby the broaches are actuated simultaneously and equally toward and away from the werk piece.

5. In a breaching machine including means for supporting a rotary Work piece, a bifurcated platen having a member located at each side of the work piece, said platen being mounted for 'reciprocatery movement past the werk piece, a pair of parallel toothed broaches, one on each of said members and spaced apart en opposite sides of the center line ef the work piece, means for reciprocating the platen and broaches, a meter, and means operatively connecting the motor to the respective broaches and arranged and adapted to move the breaches coincidently with the movements of the platen and transversely to the planes defined by the cutting edges of the teeth of the respective broaches whereby the breaches are actuated simultaneously and equally toward the Work piece.

6. In a breaching machine including means for rotatably supporting a Werk piece and having a platen mounted for lengthwise reciprocatery movement past the work piece, a toothed broach mounted en said platen and arranged for lateral movement relatively thereto, means for actuating both the platen and broach together in the direction ci the length of the breach; a motor, and means including a tapered longitudinally slidable feed bar operatively connecting the motor to the broach and adapted to move the broach relatively to the platen in a lateral direction transverse to a plane defined by the cutting edges of the broach teeth, the operation of the motor being coincidental with the reciprocatery movement of the platen.

'7. In a breaching machine including means for rotatably supporting a Work piece and having a platen mounted for lengthwise reciprocatery movement past the work piece, a toothed broach mounted en said platen and arranged for lateral feeding-in movement relatively thereto, means for reciprocating both the platen and breach together in the direction of the length of the broach; a meter, and cam means operatively connecting the motor to the broach and adapted to move the breach relatively to the platen in a feeding-in direction transverse te the plane defined by the cutting edges of the broach teeth and coincidental with the reciprocatery movement of the platen. 1 l

FREDERICK S. FLOETER. 

